scholarly journals Global change-type drought-induced tree mortality: vapor pressure deficit is more important than temperature per se in causing decline in tree health

2013 ◽  
Vol 3 (8) ◽  
pp. 2711-2729 ◽  
Author(s):  
Derek Eamus ◽  
Nicolas Boulain ◽  
James Cleverly ◽  
David D. Breshears
Keyword(s):  
Global Change ◽  
Vapor Pressure ◽  
Tree Mortality ◽  
Vapor Pressure Deficit ◽  
Tree Health ◽  
Change Type ◽  
Per Se

A consistent link between drought and forest diebacks across Europe

2020 ◽  
Author(s):  
Cornelius Senf ◽  
Allan Buras ◽  
Christian Zang ◽  
Anja Rammig ◽  
Rupert Seidl
Keyword(s):  
Vapor Pressure ◽  
Large Scale ◽  
Tree Mortality ◽  
Vapor Pressure Deficit ◽  
Tree Canopy ◽  
Drought Indices ◽  
Spatially Explicit ◽  
Quantitative Evidence ◽  
Drought Conditions ◽  
Landsat Satellite

<p>Drought has been suggested as major driver of large-scale forest diebacks, but quantitative evidence covering large spatial and long temporal scales is rare for Europe. Combining spatially explicit maps of canopy mortality (i.e., partial or full loss of the dominant tree canopy) generated from Landsat satellite data for the period 1986-2016 and gridded drought indices (0.5° resolution; including vapor pressure deficit, climatic water balance, and precipitation deficit), we report a consistent link between pulses of above-average tree mortality and drought conditions as measured in all three drought indices. As such, we deliver first quantitative evidence that drought conditions can trigger large-scale forest diebacks across Europe’s forests. A future increase in the severity and intensity of droughts as predicted for Europe might thus have unforeseen consequences for Europe’s forests, with large-scale forest diebacks likely becoming more common in the future.</p>

Effect of Mycorrhizal Fungi on Gas Exchange of Micropropagated Guava Plantlets (Psidium guajava L.) during Acclimatization and Plant Establishment

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 501c-501
Author(s):  
Andrés A. Estrada-Luna ◽  
Jonathan N. Egilla ◽  
Fred T. Davies
Keyword(s):  
Tissue Culture ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Vapor Pressure ◽  
Mycorrhizal Fungi ◽  
Vapor Pressure Deficit ◽  
Psidium Guajava ◽  
Glomus Etunicatum ◽  
Plant Establishment ◽  
Use Efficiency

The effect of mycorrhizal fungi on gas exchange of micropropagated guava plantlets (Psidium guajava L.) during acclimatization and plant establishment was determined. Guava plantlets (Psidium guajava L. cv. `Media China') were asexually propagated through tissue culture and acclimatized in a glasshouse for eighteen weeks. Half of the plantlets were inoculated with ZAC-19, which is a mixed isolate containing Glomus etunicatum and an unknown Glomus spp. Plantlets were fertilized with modified Long Ashton nutrient solution containing 11 (g P/ml. Gas exchange measurements included photosynthetic rate (A), stomatal conductance (gs), internal CO2 concentration (Ci), transpiration rate (E), water use efficiency (WUE), and vapor pressure deficit (VPD). Measurements were taken at 2, 4, 8 and 18 weeks after inoculation using a LI-6200 portable photosynthesis system (LI-COR Inc. Lincoln, Neb., USA). Two weeks after inoculation, noninoculated plantlets had greater A compared to mycorrhizal plantlets. However, 4 and 8 weeks after inoculation, mycorrhizal plantlets had greater A, gs, Ci and WUE. At the end of the experiment gas exchange was comparable between noninoculated and mycorrhizal plantlets.

scholarly journals Is There Daily Growth Hysteresis versus Vapor Pressure Deficit in Cherry Fruit?

Horticulturae ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 131
Author(s):  
Matteo Zucchini ◽  
Arash Khosravi ◽  
Veronica Giorgi ◽  
Adriano Mancini ◽  
Davide Neri
Keyword(s):  
Vapor Pressure ◽  
Vapor Pressure Deficit ◽  
Fruit Growth ◽  
Hysteresis Curve ◽  
Growth Stages ◽  
Fourth Stage ◽  
The Third ◽  
Third Stage ◽  
Rainy Days ◽  
Clockwise Hysteresis

The growth of cherry fruit is generally described using a double sigmoid model, divided into four growth stages. Abiotic factors are considered to be significant components in modifying fruit growth, and among these, the vapor pressure deficit (VPD) is deemed the most effective. In this study, we investigated sweet cherry fruit growth through the continuous, hourly monitoring of fruit transversal diameter over two consecutive years (2019 and 2020), from the beginning of the third stage to maturation (forth stage). Extensometers were used in the field and VPD was calculated from weather data. The fruit growth pattern up to the end of the third stage demonstrated three critical steps during non-rainy days: shrinkage, stabilization and expansion. In the third stage of fruit growth, a partial clockwise hysteresis curve of circadian growth, as a response to VPD, appeared on random days. The pattern of fruit growth during rainy days was not distinctive, but the amount and duration of rain caused a consequent decrease in the VPD and indirectly boosted fruit growth. At the beginning of the fourth stage, the circadian growth changed and the daily transversal diameter vs VPD formed fully clockwise hysteresis curves for most of this stage. Our findings indicate that hysteresis can be employed to evaluate the initial phenological phase of fruit maturation, as a fully clockwise hysteresis curve was observable only in the fourth stage of fruit growth. There are additional opportunities for its use in the management of fruit production, such as in precision fruit farming.

scholarly journals Towards In Vivo Monitoring of Ions Accumulation in Trees: Response of an in Planta Organic Electrochemical Transistor Based Sensor to Water Flux Density, Light and Vapor Pressure Deficit Variation

2021 ◽  
Vol 11 (11) ◽  
pp. 4729
Author(s):  
Davide Amato ◽  
Giuseppe Montanaro ◽  
Filippo Vurro ◽  
Nicola Coppedé ◽  
Nunzio Briglia ◽  
...  
Keyword(s):  
Vapor Pressure ◽  
Flux Density ◽  
Precision Agriculture ◽  
Vapor Pressure Deficit ◽  
Accumulation Rate ◽  
Xylem Sap ◽  
Water Flux ◽  
Electrochemical Transistor ◽  
Olive Trees

Research on organic electrochemical transistor (OECT) based sensors to monitor in vivo plant traits such as xylem sap concentration is attracting attention for their potential application in precision agriculture. Fabrication and electronic aspects of OECT have been the subject of extensive research while its characterization within the plant water relation context deserves further efforts. This study tested the hypothesis that the response (R) of an OECT (bioristor) implanted in the trunk of olive trees is inversely proportional to the water flux density flowing through the plant (Jw). This study also examined the influence on R of vapor pressure deficit (VPD) as coupled/uncoupled with light. R was hourly recorded in potted olive trees for a 10-day period concomitantly with Jw (weight loss method). A subgroup of trees was bagged in order to reduce VPD and in turn Jw, and other trees were located in a walk-in chamber where VPD and light were independently managed. R was tightly sensitive to diurnal oscillation of Jw and at negligible values of Jw (late afternoon and night) R increased. The bioristor was not sensitive to the VPD per se unless a light source was coupled to trigger Jw. This study preliminarily examined the suitability of bioristor to estimate the mean daily nutrients accumulation rate (Ca, K) in leaves comparing chemical and sensor-based procedures showing a good agreement between them opening new perspective towards the application of OECT sensor in precision agricultural cropping systems.

Effect of vapor pressure deficit on the photosynthesis, growth, and nutrient absorption of tomato seedlings

2021 ◽  
pp. 110736
Author(s):  
Juping Ding ◽  
Xiaocong Jiao ◽  
Ping Bai ◽  
Yixin Hu ◽  
Jiayu Zhang ◽  
...  
Keyword(s):  
Vapor Pressure ◽  
Vapor Pressure Deficit ◽  
Nutrient Absorption ◽  
Tomato Seedlings

Transpiration Response to Vapor Pressure Deficit in Field Grown Peanut

2012 ◽  
Vol 39 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Maria Balota ◽  
Steve McGrath ◽  
Thomas G. Isleib ◽  
Shyam Tallury
Keyword(s):  
Vapor Pressure ◽  
Soil Water ◽  
Water Deficit ◽  
Water Conservation ◽  
Vapor Pressure Deficit ◽  
Stomatal Closure ◽  
Genotypic Variation ◽  
Moisture Stress ◽  
Breeding Lines ◽  
Wide Range

Abstract Water deficit, i.e., rainfall amounts and distribution, is the most common abiotic stress that limits peanut production worldwide. Even though extensive research efforts have been made to improve drought tolerance in peanut, performance of genotypes largely depends upon the environment in which they grow. Based on greenhouse experiments, it has been hypothesized that stomata closure under high vapor pressure deficit (VPD) is a mechanism of soil water conservation and it has been shown that genotypic variation for the response of transpiration rate to VPD in peanut exists. The objective of this study was to determine the relationship between stomatal conductance (gs) and VPD for field grown peanut in Virginia-Carolina (VC) rainfed environments. In 2009, thirty virginia-type peanut cultivars and advanced breeding lines were evaluated for gs at several times before and after rain events, including a moisture stress episode. In 2010, eighteen genotypes were evaluated for gs under soil water deficit. In 2009, VPD ranged from 1.3 to 4.2 kPa and in 2010 from 1.78 to 3.57 kPa. Under water deficit, genotype and year showed a significant effect on gs (P  =  0.0001), but the genotype × year interaction did not. During the water deficit episodes while recorded gs values were relatively high, gs was negatively related to VPD (R2  =  0.57, n  =  180 in 2009; R2  =  0.47, n  =  108 in 2010), suggesting that stomata closure is indeed a water conservation mechanism for field grown peanut. However, a wide range of slopes among genotype were observed in both years. Genotypes with significant negative relationships of gs and VPD under water deficit in both years were Florida Fancy, Gregory, N04074FCT, NC-V11, and VA-98R. While Florida Fancy, Gregory, and NC-V11 are known to be high yielding cultivars, VA-98R and line N04074FCT are not. The benefit of stomatal closure during drought episodes in the VC environments is further discussed in this paper.

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